let a = 'aaa'
let b = 123
let c = true
let d = undefined
let e = null
let f = Symbol('f')
let g = BigInt(312312313134n)

let obj = {}
let arr = []
let fn =function(){}

console.log(typeof(a));
console.log(typeof(b));
console.log(typeof(c));
console.log(typeof(d));
console.log(typeof(e));//string
console.log(typeof(f));
console.log(typeof(g));
console.log(typeof(obj));
console.log(typeof(arr));//object
console.log(typeof(fn));

console.log(obj instanceof Object);
console.log(arr instanceof Array);
console.log(fn instanceof Function);


console.log(Object.prototype.toString.call(a));
